The three most common reasons trees are pruned are to make trees safe, improve tree health, and increase tree beauty. All of these tree concerns can usually be accomplished each time a tree is pruned. How often trees should be pruned is dependent on the tree species, tree health, and tree location, but is normally every 3- 5 years.
Safety Pruning of Trees
Increasing tree safety generally involves the pruning of dead tree branches, broken tree branches, or hanging tree branches. Dead, broken, or hanging tree branches might fall at anytime and cause property damage or injure someone under the tree.
Pruning of tree branches that block views of driveways or roads is another aspect of improving tree safety. This type of tree pruning usually involves the removal of low tree branches, but may occasionally involve crown reduction.
Utility companies regularly prune tree branches that are too close to power wires. It should be noted, however, that they will not prune tree branches that are too close to phone or cable TV wires.
Tree Pruning To Improve Tree Health
Tree pruning can improve tree health by removing dead tree branches, diseased tree branches, or insect infested tree branches. The development of dead branches in trees is a natural occurrence because certain branches become shaded out by an ever expanding tree canopy. Eventually the dead tree branches will break and leave a stub or a wound on the tree trunk. Pruning these branches before they break will reduce the potential for decay to enter the tree trunk because a proper pruning cut will heal quickly.
Thinning of live tree branches from the tree canopy can improve tree health by reducing the potential for storm damage. Increased airflow in the canopy of a tree will allow the wind to blow through, instead of against the tree, and will also reduce leaf infection by some tree diseases.
Tree pruning, especially pruning young trees, can be done to improve tree structure. Developing a strong tree structure will not only improve long term tree health but will improve the beauty of the tree. Storm damage is less likely to occur if the tree has been pruned to encourage a strong tree structure.
Tree Pruning To Increase Tree Beauty
Trees come in many forms; there are pyramidal trees, trees with rounded forms, columnar trees, and weeping trees. The natural form and character of each tree needs to be considered before pruning the tree. Changing the natural form of the tree can be done, but will increase the maintenance cost associated with the tree and may shorten the lifespan of the tree. Working with the natural form of the tree not only reduces maintenance costs but usually results in a healthier tree.
Tree pruning to improve the view of a lake or the surrounding topography is known as vista pruning or view pruning. This type of tree pruning most often involves the removal of low tree branches or reducing the crown of a tree. An experienced arborist, preferably an ISA Certified Arborist, should be consulted if crown reduction is necessary. Proper crown reduction is not the same a tree topping.
Specialized Tree Pruning
In rare instances trees are intentionally pruned without regard to their natural form to achieve a desired result. This type of tree pruning is known as pollarding, topiary pruning, or espalier pruning.
Pollarding is begun after the tree reaches the desired height or width and involves the annual removal of all new growth on the tree. New growth sprouts out at the ends of each branch in the spring.
Topiary is the practice of pruning trees, shrubs, or vines into identifiable shapes. Trees, shrubs, or vines may be shaped into stars, triangles, squares, or even animal shapes. With enough time and imagination, trees, shrubs, or vines can be shaped into almost any form.
Espalier pruning involves pruning trees or shrubs that are intentionally planted close to a wall or fence. Selected tree or shrub branches are trained to grow horizontally next to the wall or fence. Meticulous pruning keeps plant growth close to the wall or fence.